# IUniswapV3PoolDerivedState

Contains view functions to provide information about the pool that is computed rather than stored on the blockchain. The functions here may have variable gas costs.

## Functions

### observe

` function observe(`

uint32[] secondsAgos

) external view returns (int56[] tickCumulatives, uint160[] secondsPerLiquidityCumulativeX128s)

Returns the cumulative tick and liquidity as of each timestamp `secondsAgo`

from the current block timestamp

To get a time weighted average tick or liquidity-in-range, you must call this with two values, one representing the beginning of the period and another for the end of the period. E.g., to get the last hour time-weighted average tick, you must call it with secondsAgos = [3600, 0]. The time weighted average tick represents the geometric time weighted average price of the pool, in log base sqrt(1.0001) of token1 / token0. The TickMath library can be used to go from a tick value to a ratio.

#### Parameters:

Name | Type | Description |
---|---|---|

`secondsAgos` | uint32[] | From how long ago each cumulative tick and liquidity value should be returned |

#### Return Values:

Name | Type | Description |
---|---|---|

`tickCumulatives` | int56[] | Cumulative tick values as of each `secondsAgos` from the current block timestamp |

`secondsPerLiquidityCumulativeX128s` | uint160[] | Cumulative seconds per liquidity-in-range value as of each `secondsAgos` from the current block |

timestamp

### snapshotCumulativesInside

` function snapshotCumulativesInside(`

int24 tickLower,

int24 tickUpper

) external returns (int56 tickCumulativeInside, uint160 secondsPerLiquidityInsideX128, uint32 secondsInside)

Returns a snapshot of the tick cumulative, seconds per liquidity and seconds inside a tick range

Snapshots must only be compared to other snapshots, taken over a period for which a position existed. I.e., snapshots cannot be compared if a position is not held for the entire period between when the first snapshot is taken and the second snapshot is taken.

#### Parameters:

Name | Type | Description |
---|---|---|

`tickLower` | int24 | The lower tick of the range |

`tickUpper` | int24 | The upper tick of the range |

#### Return Values:

Name | Type | Description |
---|---|---|

`tickCumulativeInside` | int56 | The snapshot of the tick accumulator for the range |

`secondsPerLiquidityInsideX128` | uint160 | The snapshot of seconds per liquidity for the range |

`secondsInside` | uint32 | The snapshot of seconds per liquidity for the range |